Amnesiac (noun)

A person affected by amnesia; someone with a partial or total loss of memory.

Origin:

Originated in the mid-20th century, from 'amnesia'.

Examples:

1. The amnesiac could not remember anything about his past.
2. The accident left her an amnesiac, unable to recall even the simplest details.
3. The film tells the story of an amnesiac who wakes up with no memory of who he is.
4. The patient was diagnosed as an amnesiac and given treatment to improve his memory.
5. The amnesiac struggled to piece together his fragmented memories.